Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753803AbbLCUZb (ORCPT ); Thu, 3 Dec 2015 15:25:31 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:32420 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753607AbbLCUZ3 (ORCPT ); Thu, 3 Dec 2015 15:25:29 -0500 From: Babu Moger To: bhelgaas@google.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, babu.moger@oracle.com Subject: [PATCH v4] pci: Limit VPD length for megaraid_sas adapter Date: Thu, 3 Dec 2015 12:25:19 -0800 Message-Id: <1449174319-52798-1-git-send-email-babu.moger@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1447957102-184860-1-git-send-email-babu.moger@oracle.com> References: <1447957102-184860-1-git-send-email-babu.moger@oracle.com> X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3982 Lines: 101 Reading or Writing of PCI VPD data causes system panic. We saw this problem by running "lspci -vvv" in the beginning. However this can be easily reproduced by running cat /sys/bus/devices/XX../vpd VPD length has been set as 32768 by default. Accessing vpd will trigger read/write of 32k. This causes problem as we could read data beyond the VPD end tag. Behaviour is un- predictable when this happens. I see some other adapter doing similar quirks(commit bffadffd43d4 ("PCI: fix VPD limit quirk for Broadcom 5708S")) I see there is an attempt to fix this right way. https://patchwork.ozlabs.org/patch/534843/ or https://lkml.org/lkml/2015/10/23/97 Tried to fix it this way, but problem is I dont see the proper start/end TAGs(at least for this adapter) at all. The data is mostly junk or zeros. This patch fixes the issue by setting the vpd length to 0x80. Signed-off-by: Babu Moger Reviewed-by: Khalid Aziz Tested-by: Dmitry Klochkov Orabug: 22104511 Changes since v3 -> v4 We found some options of the lspci does not work very well if it cannot find the valid vpd tag(Example command "lspci -s 10:00.0 -vv"). It displays the error message and exits right away. Setting the length back to 0 fixes the problem. Changes since v2 -> v3 Changed the vpd length from 0 to 0x80 which leaves the option open for someone to read first few bytes. Changes since v1 -> v2 Removed the changes in pci_id.h. Kept all the vendor ids in quirks.c --- drivers/pci/quirks.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 38 insertions(+), 0 deletions(-) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index b03373f..f739e47 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -2123,6 +2123,44 @@ static void quirk_via_cx700_pci_parking_caching(struct pci_dev *dev) DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); /* + * A read/write to sysfs entry ('/sys/bus/pci/devices//vpd') + * will dump 32k of data. The default length is set as 32768. + * Reading a full 32k will cause an access beyond the VPD end tag. + * The system behaviour at that point is mostly unpredictable. + * Also I dont believe vendors have implemented this VPD headers properly. + * Atleast I dont see it in following megaraid sas controller. + * That is why adding the quirk here. + */ +static void quirk_megaraid_sas_limit_vpd(struct pci_dev *dev) +{ + if (dev->vpd) + dev->vpd->len = 0; +} + +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, + quirk_megaraid_sas_limit_vpd); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, + quirk_megaraid_sas_limit_vpd); + +/* * For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the * VPD end tag will hang the device. This problem was initially * observed when a vpd entry was created in sysfs -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/